v1 is the frequency of the series limit of Lyman series, v2 is the frequency of the first line of Lyman series and v3 is the frequency of the series limit of the Balmer series. Then
v1 − v2 = v3
v1 = v2 − v3
Assume the graph of specific binding energy versus mass number is as shown in the figure. Using this graph, select the correct choice from the following.
Fusion of two nuclei of mass number lying in the range of 100 < A < 200 will release energy
Fusion of two nuclei of mass number lying in the range of 51 < A < 100 will release energy
Fusion of two nuclei of mass number lying in the range of 1 < A < 50 will release energy
Fission of the nucleus of mass number lying in the range of 100 < A < 200 will release energy when broken into two fragments
Pick out the correct statement from the following.
Energy released per unit mass of the reactant is less in case of fusion reaction
Packing fraction may be positive or may be negative
Pu239 is not suitable for a fission reaction
For stable nucleus, the specific binding energy is low
A radioactive sample S1 having the activity A1 has twice the number of nuclei as another sample S2 of activity A2. If A1 = 2A1, then the ratio of half-life of S2 to the half-life of S2 is
4
2
0.25
0.75
When a neutron is disintegrated to give a β-particle,
a neutrino alone is emitted
a proton and neutrino are emitted
a proton alone is emitted
a proton and an antineutrino are emitted
The forbidden energy gap in Ge is 0.72 eV, Given, hc = 12400 eV- . The maximum wavelength of radiation that will generate electron hole pair is
In a p-n junction diode not connected to any circuit
the potential is the same everywhere
the p-type side has a higher potential than the n-type side
there is an electric field at the junction directed from the n-type side to p-type side
there is an electric field at the junction directed from the p-type side to n-type side
In a given direction, the intensities of the scattered light by a scattering substance for two beams of light are in the ratio of 256 : 81. The ratio of the frequency of the first beam to the frequency of the second beam is
64 : 127
1 : 2
64 : 27
None of these
The de-Broglie wavelength ofthe electron in the ground state of the hydrogen atom is (radius of the first orbit of hydrogen atom = 0.53 )
B.
According to Bohr's quantisation of angular momentum
de-Broglie wavelength
From Eqs. (i) and (ii), we get